#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define vl vector<ll>
#define pi pair<int, int>
#define pl pair<ll,ll>
#define all(x) (x).begin(),(x).end()
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n,m,k;
cin >> n >> m >> k;
vi a(n);
vi b(m);
for (int i=0; i<n; i++) {
cin >> a[i];
}
for (int i=0; i<m; i++) {
cin >> b[i];
}
int s=accumulate(all(b),0);
int s2=accumulate(all(a),0);
if (*min_element(all(a))<k || m<k || s<s2) {
cout << "Impossible\n";
return 0;
}
bool dp[m+1][s+1];
memset(dp,0,sizeof(dp));
dp[0][0]=1;
for (int i=0; i<m; i++) {
for (int l=0; l<=s; l++) {
if (!dp[i][l]) {
continue;
}
dp[i+1][l]=1;
dp[i+1][l+b[i]]=1;
}
}
int ans=1e9;
for (int k=s2; k<=s; k++) {
if (dp[m][k]) {
ans=min(ans,k-s2);
}
}
if (ans==1e9) {
cout << "Impossible\n";
}
else {
cout << ans << '\n';
}
return 0;
}
